/*
 * 快捷样式lib
 */
// size
.size(@height, @width) {
  width: @width;
  height: @height;
}

.square(@size) {
  .size(@size, @size);
}

// Center-align a block level element
.center-block() {
  display: block;
  margin-left: auto;
  margin-right: auto;
}